package com.cargo.base.utils;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class AESUtil {
	// 加密
	public static String Encrypt(String sSrc, String sKey) throws Exception {
		if (sKey == null) {
			System.out.print("Key为空null");	
			return null;
		}
		// 判断Key是否为16位
		if (sKey.length() != 16) {
			System.out.print("Key长度不是16位");
			return null;
		}
		byte[] raw = sKey.getBytes("utf-8");
		SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
		Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");// "算法/模式/补码方式"
		cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
		byte[] encrypted = cipher.doFinal(sSrc.getBytes("utf-8"));

		BASE64Encoder encoder = new BASE64Encoder();
		encoder.encode(encrypted);

		return encoder.encode(encrypted);// 此处使用BASE64做转码功能，同时能起到2次加密的作用。
	}

	// 解密
	public static String Decrypt(String sSrc, String sKey) throws Exception {
		try {
			// 判断Key是否正确
			if (sKey == null) {
				System.out.print("Key为空null");
				return null;
			}
			// 判断Key是否为16位
			if (sKey.length() != 16) {
				System.out.print("Key长度不是16位");
				return null;
			}
			byte[] raw = sKey.getBytes("utf-8");
			SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
			Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
			cipher.init(Cipher.DECRYPT_MODE, skeySpec);

			BASE64Decoder decoder = new BASE64Decoder();

			byte[] encrypted1 = decoder.decodeBuffer(sSrc);// 先用base64解密

			try {
				byte[] original = cipher.doFinal(encrypted1);
				String originalString = new String(original, "utf-8");
				return originalString;
			} catch (Exception e) {
				System.out.println(e.toString());
				return null;
			}
		} catch (Exception ex) {
			System.out.println(ex.toString());
			return null;
		}
	}

	/**
	 * 获得秘钥加密
	 * 
	 * @param key
	 * @return
	 * @throws Exception
	 */
	public static String getSecKey(String key, String licKey) throws Exception {
		String secKey = "";

		secKey = Encrypt(key, licKey.substring(0, 16));

		return secKey;
	}

	/**
	 * 许可证秘钥用AES再加密
	 * 
	 * @param licKey
	 * @param secKey
	 * @return
	 * @throws Exception
	 */
	public static String getLicKeyC(String licKey, String secKey) throws Exception {

		return AESUtil.Encrypt(licKey, secKey.substring(0, 16));

	}

	/**
	 * 获得解密密钥
	 * 
	 * @param licKey
	 * @return
	 * @throws Exception
	 */
	public static String getCKey(String licKey, String secKey) throws Exception {
		String cKey = "";

		licKey = Decrypt(licKey, secKey.substring(0, 16));

		cKey = Decrypt(secKey, licKey.substring(0, 16));

		return cKey;
	}

	/**
	 * 补全秘钥为16位
	 * 
	 * @param keyString
	 * @return
	 */
	public static String padkey(String keyString) {
		String returnCode = "";
		if (keyString.length() > 16) {
			returnCode = keyString.substring(0, 16);
		}
		if (keyString.length() == 16) {
			returnCode = keyString;
		}
		if (keyString.length() < 16) {
			int padLength = 16 - keyString.length();
			for (int i = 0; i < padLength; i++) {
				keyString += "0";
			}
			returnCode = keyString;
		}
		return returnCode;
	}

}
